The present invention relates to mechanisms for typewriters that utilize printing ribbon cartridges in general and include those of the type disclosed in U.S. Pat. No. 3,643,777 entitled TYPEWRITER RIBBON CARTRIDGE granted Feb. 22, 1972 and United States patent Application Ser. No. 150,946 filed June 9, 1971 with Carl Anderson et al. as inventors and entitled TYPEWRITER RIBBON CARTRIDGE both of which are assigned to the assignee of the instant application. The term "cartridge" as used hereinafter is defined to include any form of ribbon holder or container irrespective of configuration and the manner of insertion into the typewriter.
More particularly, the present invention relates to typewriters and to the automatic actuation of typewriter functions upon removal of the ribbon cartridge.
The term "typewriter function" is defined to include any typewriter operation which provides for the alignment of a selected platen impact point relative to the typewriter print point.
One particularly useful typewriter function that may be accomplished by the actuating mechanism of this invention is to provide an automatic backspace operation upon removal of an inserted cartridge. A typical backspace operation that may be automated by the actuating mechanism of this invention is fully disclosed in U.S. Pat. No. 3,482,671 entitled BACK SPACE MECHANISM FOR TYPEWRITERS granted on Dec. 9, 1969 with Richard Shattuck as inventor and assigned to the same assignee as the instant application. When cooperating with a modified cartridge, housing an error correction tape therein, the final manipulative step previously necessary for an error correction operation is directly eliminated.
Error correction devices require a series of sequential manual operations of the typewriter. For example, when an operator typed an erroneous character, it was first necessary to depress the backspace key to actuate the backspace mechanism, thereby repositioning the typewriter carriage to the proper printing station for making the correction. The typist would then overstrike the erroneously typed character through a correction medium to the writing paper, thereby rendering the erroneous character semi-invisible. Another backspace operation would then be necessary to again reposition the typewriter carriage to the proper printing station so that the correct character may be typed over the correction material. Therefore, a series of manipulative operations by the operator are necessary to correct each erroneously typed character. The end result of the foregoing is that the typing speed is significantly reduced relative to the amount of erroneous characters typed, thereby significantly increasing the time and the cost required for the preparation of typed material.
The present invention as applied to error correction, reduces the number of backspace operations that are necessary to perform an error correcting operation in that the final backspace operation is automated.
The invention is clearly not intended to apply only to the foregoing, but may readily be applied in conjunction with any related typewriter function.
Other advantages of the present invention will become more fully apparent from the following description, drawings, and appended claims.